Methane Not Detected by Curiosity Rover Does Not Rule Out Life on Mars

NASA released a statement yesterday reporting that the Curiosity Rover has not detected methane on Mars, but this does not rule out the possibility of life on the neighboring planet.

Methane in the atmosphere of Mars could have pointed to signs of life because the production of methane by microbes is a prevalent form of microbial metabolism on Earth. If the rover had found traces of methane, it could have led to the discovery of these types of microbes on another planet. Of course, not all microbial life forms produce methane gas, so these findings do not rule out the possibility of life on Mars.

Scientists hoped that Curiosity would detect methane because they thought they had detected it on Mars in the past. In early 2009, astronomers reported evidence of plumes of methane gas emanating from a specific region. A geological survey of the area indicated that the gas was seeping out from a zone with similar geology to Earth during the warmer summer months. They pinpointed the location of the release to an area on the western hemisphere of Mars called Nili Fossae. The Curiosity Rover is in the Gale Crater which is located very near the planet’s equator in the eastern hemisphere. If they had been correct, the rover, with the ability to detect methane in as little concentrations as one part per billion and below, would have found the gas. The previous reports indicated methane in concentrations of up to 45 parts per billion, which is inconsistent with the newest data collected. So, what happened to the methane?

In their recent announcement, NASA explains that if methane had been dispersed into the atmosphere of Mars, as they expected, it would have persisted for hundreds years. There is no known way for the methane to have escaped the planet from the time we detected it in 2009 to the time Curiosity collected its data during the interval of the last Martian spring to late summer. It would have been trapped in the atmosphere of the planet with no way of escape. Despite the distance from Nili Fossae to the Gale Crater, Curiosity would have detected the methane.

The question we are left with is, what exactly was it that we observed from here on Earth and through orbit of the red planet, back in 2009? Even though methane has not been detected by the Curiosity Rover, we did notice some kind of mysterious activity originally thought to be the gas. At this time, with so many questions, we cannot rule out the possibility of life on Mars.

“It would have been exciting to find methane, but we have high confidence in our measurements, and the progress in expanding knowledge is what’s really important,” said the NASA report’s lead author, Chris Webster of NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

In science, contradictory results can lead to extraordinary discoveries. Einstein discovered the theory of relativity because he noticed contradictions in the then current studies of electromagnetism. Since the measurements taken by Curiosity are inconsistent with the 2009 results, we have to keep our fingers crossed that the rover’s data collected over the next few years will help solve this mystery and perhaps even discover life on Mars.